True armyworm

Adult - The true armyworm moth has grayish-brown forewings, each with a white spot near the center, and grayish-white hind wings. The wingspan averages 38.5 mm.
Egg - The minute, greenish-white egg is globular in shape.
Larva - The young armyworm is pale green. The mature larva is basically yellowish or brownish-green with a tan or greenish-brown head mottled with darker brown. The smooth, practically hairless body is marked with three dark longitudinal stripes, one along each side and one down the back. A full-grown armyworm is 30 to 35 mm long.
Pupa - The reddish-brown 13-mm-long pupa darkens gradually until it is almost black.
Damage - Preferring to feed at night, armyworms devour succulent foliage. By feeding on leaves and occasionally stems, they can severely damage seedling stands. Because they feed at night, armyworms may inflict much injury before they are detected. Having exhausted a current food supply, the worms migrate as an "army" to new host plants. Fields adjacent to or harboring lush grass are most commonly attacked.